| Popis: |
The region studied on the Taquari River, is close to a site with soil contaminated by wood preservatives, where a route of contaminants into the river was identified. This site was submitted to the first stage of the intervention process excavating the soil to remove the main active sources. To assess sediment quality the PAHs concentrations were analyzed: before, during and after the process. The PAHs concentration was compared to the guide values adopted by CONAMA resolution 344/04, aiming to protect aquatic life. Four points on Taquari River were tested, upper (TA032), in front (TA010) and lower (TA006, TA004) the contaminated site. Besides these, the Stream that is considered a source of contamination for TA010 was evaluated in the last step. The results indicated values between ISQG (Interim Sediment Quality Guidelines and PEL (Probable Effect Level) observed for eight PAHs. The PAHs values, probably carcinogenic to humans, were between ISQG and PEL in different samplings at TA010, more expressives during and after intervention. These values were also found at TA006 and TA004 during the same periods. The persistent contamination of the critical point TA010, even after intervention, is a warning regarding the environmental quality and aquatic life of this region. |
